Product Description

Disposable warmers can be used any time
instant warmth is needed.

They were introduced in Japan
about 30 years ago.
Today, millions are sold annually around the World.

Warmers are activated by simply opening the package
and exposing the packet to air.
Once shaken gently,
they start to generate heat in minutes.
In order to work properly, pad must be kept covered.
It generates warm for about 20 hours.

Partially used warmer can be reused again
for another time, preferably within a week.
Just wrap the warmer in plastic or aluminum foil
to seal out air and put it in the cold place,
as cold slows chemical reactions.

Features

Soft light-weight pouch,
containing a mixture of iron powder, charcoal, salt, sawdust, and vermiculite.
When exposed to the air,
oxidation process takes place that generates heat.
Unopened, the Heat Factory warmers claim a shelf life
of three years.

Small warmers are 2-1/4" X 3".

Links

Images

Bought 4 of those at Gigasport(Graz/Austria) shop sellaout.
Price was about 0.99 eurocents each.

Small pads are primarly aimed for hands warming
(there are larger packs available from the same manufacturer).
Used couple of warmers simultaneously inside the bivysack,
result was satisfactory.
That said, outdoor temperature was around 6 or 7 degrees C (44 F).

They do the job, and are reusable as claimed
(used one of them 4 times during the multiday cycling trip).

Once these pads are done...well, they are done.
Still, hard to beat the price.